DNS behaviors of the Cisco router are important topics for each the CCNA exam and genuine-earth creation networks, and you almost certainly did not know there have been a lot of DNS information prior to deciding to began finding out for the Examination! During this tutorial, we are going to look at the ip title-server command and its correct usage.
Whenever a command is mistyped over a Cisco router, the default actions on the router is always to try to resolve it by means of DNS. 1st, the router looks for an IP Host table on the local router to complete this resolution – that’s what the “translating” phrase while in https://www.keepsolid.com/smartdns/manuals/tomato-dns-setup the output is referring to. If there’s no IP Host desk or even the IP Host desk will not contain an entry for That which you typed, the router will send out a broadcast in an make an effort to resolve this identify via a distant DNS server. To avoid this broadcast, enter the worldwide command no ip domain-lookup. Obviously, to utilize DNS to take care of hostnames, ip area-lookup would need to be reenabled if it has been turned off.
Translating “contin”…area server (255.255.255.255)
% Unknown command or Laptop name, or unable to locate computer deal with
A command is mistyped as “contin”. The Cisco router’s default conduct should be to solve this entry locally by way of an IP Host desk, which is just not current to the router. A broadcast is then despatched out to find a DNS server to complete the name resolution. The DNS lookup attempt have to time out before the configuration can carry on.
R2(config)#no ip area-lookup
% Mysterious command or Computer system title, or not able to obtain Personal computer tackle
With “no ip area-lookup” configured, the router won’t make an effort to discover a distant DNS server. It sees there isn’t any area resolution configured and presently sends a concept for the console the identify can’t be settled.
R2(config)#ip identify-server ten.one.1.1
Translating “contin”…domain server (ten.one.one.one)
A DNS server is set up within the community with the IP address ten.one.1.one. DNS lookup is reenabled Along with the command ip domain-lookup, as well as the IP deal with of your DNS server is specified Together with the ip title-server command.
It is just that simple to inform a Cisco router accurately where the DNS server is!